1. Field of the Invention
This invention pertains to typewriters and printer ribbon guidance mechanisms and structures and to ribbon cartridges.
2. Description of the Prior Art
Many forms of factory pre-threaded ribbon cartridges for installation on the travelling print carriage of a typewriter or printer are shown in the prior art but the means employed are not generally applicable to articulated or compliant ribbon-guiding structures of the types shown in my U.S. Pat. Nos. 4,047,607 and 4,047,608 which are incorporated herein by reference. U.S. Pat. Nos. 4,277,187 and 4,284,364 show the application of a spreader bar or bridge to the outer ends of two flexible ribbon-guiding members to maintain a fixed separation and to provide a means of attachment to the print carriage. An early application of one type of spreader bar is shown in U.S. Pat. No. 2,074,778 to locate two loops of ribbon. A structure having a spreader bar attached to the outer ends of two flexible or compliant ribbon guides is not collapsible or foldable to any useful degree and hence requires an additional inordinate amount of packaging space or volume over requirements for the cartridge itself.